MK1 MX5 plugs getting wet?
Discussion
My girlfriend has a MK1 MX5 and her commute is through the back roads. It seems that water is splashing up and taking out a spark plug or two as her engine starts to run and idle rough. Let it dry out and it goes back to normal.
Can you get a cover for the plugs? Or are the seals between the plugs to engine block replaceable or....are we guessing wrong?
Can you get a cover for the plugs? Or are the seals between the plugs to engine block replaceable or....are we guessing wrong?
I very much doubt it would be water splashing up unless the leads feel very damp. It would only be a problem if the leads were knackered anyway.
My guess would be cam cover gasket failure which causes oil on the spark plugs. That's a very common one. Easy to diagnose; remove each plug and check for oil.
Failing that the plug leads might need replacing and finally if your idle is unusual or drooping you might just need to clean the intake manifold/ injectors or adjust the idle control valve. Let us know if you need further guidance with that.
Hope that helps
Pete.
My guess would be cam cover gasket failure which causes oil on the spark plugs. That's a very common one. Easy to diagnose; remove each plug and check for oil.
Failing that the plug leads might need replacing and finally if your idle is unusual or drooping you might just need to clean the intake manifold/ injectors or adjust the idle control valve. Let us know if you need further guidance with that.
Hope that helps
Pete.
Edited by Pete Franklin on Friday 4th November 22:15
I very much doubt it would be water splashing up unless the leads feel very damp. It would only be a problem if the leads were knackered anyway.
My guess would be cam cover gasket failure which causes oil on the spark plugs. That's a very common one. Easy to diagnose; remove each plug and check for oil.
Failing that the plug leads might need replacing and finally if your idle is unusual or drooping you might just need to clean the intake manifold/ injectors or adjust the idle control valve. Let us know if you need further guidance with that.
Hope that helps
Pete.
My guess would be cam cover gasket failure which causes oil on the spark plugs. That's a very common one. Easy to diagnose; remove each plug and check for oil.
Failing that the plug leads might need replacing and finally if your idle is unusual or drooping you might just need to clean the intake manifold/ injectors or adjust the idle control valve. Let us know if you need further guidance with that.
Hope that helps
Pete.
Edited by Pete Franklin on Sunday 6th November 08:47
Pete Franklin said:
I very much doubt it would be water splashing up unless the leads feel very damp. It would only be a problem if the leads were knackered anyway.
My guess would be cam cover gasket failure which causes oil on the spark plugs. That's a very common one. Easy to diagnose; remove each plug and check for oil.
Failing that the plug leads might need replacing and finally if your idle is unusual or drooping you might just need to clean the intake manifold/ injectors or adjust the idle control valve. Let us know if you need further guidance with that.
Hope that helps
Pete.
I thought it would be odd as the bonnet is solid above the plugs so I didn't see how rain would get in. Her train of thought came from a problem I had with water getting into the plugs. I have bonnet vents above my engine so rain could get in.My guess would be cam cover gasket failure which causes oil on the spark plugs. That's a very common one. Easy to diagnose; remove each plug and check for oil.
Failing that the plug leads might need replacing and finally if your idle is unusual or drooping you might just need to clean the intake manifold/ injectors or adjust the idle control valve. Let us know if you need further guidance with that.
Hope that helps
Pete.
Edited by Pete Franklin on Friday 4th November 22:15
Rain then, a while ago she had a new exhaust fitted amongst other work to get it through the MOT. Basicly ever since her idle has been slow when starting the car from cold. A while down the road (5 minutes) it would level out and run smoothly. She thought maybe the garage had done something but in her usual fashion, never got around to following it up.
The oil around the plugs, would it still be visble on a cold engine or should the engine have been run recently for best sightings?
As for the rough idle, could this be leads related/ intake related? Maybe we'll (I'll) look into this first and see if it's all related (do you think?).
Thanks for the reply.
MX-5 Lazza said:
Water should be getting anywhere near the plugs. Does it have an under-tray?
Plug leads are a common point of failure on MX5s. They get through them as fast as plugs! Replace plugs & leads together. As for a low idle, it probably just needs the base idle resetting.
How do you reset the base idle chap?Plug leads are a common point of failure on MX5s. They get through them as fast as plugs! Replace plugs & leads together. As for a low idle, it probably just needs the base idle resetting.
Resetting the base idle is only a temporary fix. There are some guides available at the end of a Google search but its as simple as shorting a couple of links in the diagnosis box and then turning a screw. If the idle is drooping (once the engine is warm) its usually due to a sooted up intake manifold / butifly valve. My advise to clean this as a longer term solution: you can take off the plastic tubing, hold the throttle butterfly half open and spray half a can of whyns injector/ carb cleaner through. Engine will start very lumpy and smokey as it burns off the cleaner but the idle should be sorted when it settles out.
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